针对煤岩的力学与渗流特性,综合考虑煤岩受力变形、损伤破坏与钻井液滤液侵入等多因素耦合条件,建立基于应力-渗流耦合的煤层井壁稳定性数值分析模型,采用弹性-应变软化-塑性模型表征煤岩的力学行为,更加准确地计算井周煤岩损伤破坏区域的尺寸与形状。研究结果表明,在井壁封堵良好的条件下,提高泥浆密度有利于稳定井壁,反之将加剧煤层井壁坍塌失稳。 Considering the mechanical and seepage characteristics of coal and rock, considering the coupled conditions of stress and seepage, such as mechanical deformation, damage and fluid intrusion, the numerical model of wellbore stability based on the stress-seepage coupling is established. The elastic- The softening-plastic model characterizes the mechanical behavior of coal and rock, and more accurately calculates the size and shape of the damaged area of ​​coal and rock in the well bore. The results show that, under well-plugged wellbore conditions, increasing the mud density is conducive to stabilizing the borehole wall, on the contrary it will aggravate the collapse and collapse of the coal seam borehole wall.